This is a pretty broad question as the answer could be any number or combination of things. Here are some of the most common causes of weak suction.

  • Your pool cleaner may be clogged with a rock, dirt or leaves.
  • You might be missing the lid o ring OR it may be missing.
  • The pump suction side and plumbing could have a suction leak.
  • The pumps impeller may be obstructed or it may have a bad weir ring or diffuser.
  • Your cleaner hoses might be cracked and sucking in air.
  • The motor bearings may be going bad causing drag on the motor.
  • There may be a high side restriction.
  • If the problem is in the high side, the pressure gauge will read above normal.
  • Another indication of blockage on the high side would be a stuck pop-up gear set assembly causing the gauge pressure to read high in-floor system.
  • You may have an obstructed filter or faulty backwash valve preventing water from going through.
  • The return lines might be accidentally closed off.